How to Convert Audible AAX to M4B [Full Guide in 2025]

Part 1. Top Audible AAX to M4B Online Converter [Free]

If you prefer a quick conversion without installing any software, an online converter like Kamsker is a convenient option. It works directly in your browser and supports basic format conversion for smaller AAX audiobook files.

How to Convert AAX to M4B Online Using Kamsker

Step 1. Visit the official Kamsker website.

Step 2. Upload your AAX audiobook from your computer by dragging and dropping it or clicking the upload area.

Step 3. Once the analysis is complete, choose M4B as the output format.

Step 4. Click Convert and wait until the process finishes.

Step 5. When the conversion is done, your AAX file will be unlocked and ready to play as a DRM-free M4B audiobook.

✅ Pros

• 100% free and web-based
• No installation required
• Simple and intuitive interface

❌ Cons

• File size limited to 900MB
• Does not support batch conversion
• Cannot retain chapters or metadata

For converting a few small AAX files, this free online method is ideal. However, for batch conversion, lossless output, or DRM-protected audiobooks, professional desktop software provides a much more stable and flexible experience. Let's explore some of the best desktop tools in the next part.

Part 2. Best AAX to M4B Converter for Mac/Windows [Paid & Free]

When dealing with large or encrypted Audible audiobooks, most online converters fall short in performance and reliability. In such cases, desktop applications deliver better speed, stability, and audio quality. Below are three of the most recommended tools you can use in 2025 to efficiently convert AAX to M4B with ease and customization.

How to Convert Audible to M4B Using AudFree Audible AAX Converter [Paid]

AudFree Audible AAX Converter is one of the most professional tools to convert Audible AAX to M4B while preserving 100% original quality and chapter information. Besides M4B, it supports multiple formats such as M4B, M4A, MP3, WAV, FLAC, and AIFF. It also allows users to split large audiobooks by chapters and edit ID3 tags. You can further customize the output with parameters like 320kbps bitrate and 48,000Hz sample rate for enhanced quality.

How to Convert Audible to M4B on Mac & Windows

Click the Download button above to install AudFree Audible Converter on your Mac or Windows computer. Then, follow the steps below to convert AAX to M4B with chapters quickly and easily.

Step 1 Import Audible AAX Files to AudFree Audible Converter

Open AudFree Audible Converter, click the "+" button, and add your downloaded Audible audiobooks to the conversion list.

Note: You'll need to activate your account before converting. The trial version only processes the first third of each audiobook.

Step 2 Set M4B as the Output Format

Click "Menu" > "Preferences" > "Convert" at the top-right corner, then choose M4B as the output format. You can also adjust bitrate, sample rate, and channel settings as needed. Don't forget to save your preferences by clicking "OK".

See also: How to Convert Audible AAX to FLAC

Step 3 Convert Audible AAX Files to M4B

Click the "Convert" button to begin the process. Once finished, tap the "Converted" icon to locate your converted M4B audiobooks with chapters. You can then transfer them to any device for offline playback.

✅ Pros

• Extremely fast and stable (up to 100× speed)
• Preserves lossless audio quality
• Handles DRM-protected AAX files
• Supports batch conversion

❌ Cons

• Free trial has limited output length

How to Convert AAX to M4B on Windows via AudioBook Converter [Free]

AudioBook Converter 6.5.2 is a lightweight Windows-based utility that allows you to transform regular AAX files into M4B audiobook format. It supports batch processing, enabling you to download M4B audiobook with chapters and bookmarks in bulk. You can also edit metadata such as title, author, and genre to better organize your audiobook collection. If you're looking for a free and effective way to convert Audible to M4B with chapters, this free tool is worth trying.

Step 1. Download and install AudioBook Converter 6.5.2 on your Windows PC.

Step 2. Launch the software and click "Add Files" to import your Audible AAX files.

Step 3. Select M4B as the output format and adjust settings such as bitrate, sample rate, and chapter options under the Quality.

Step 4. Hit the "Start" button to begin. Once finished, your converted M4B audiobooks will appear in the output folder, ready to sync with iTunes or any audiobook app.

✅ Pros

• Convert MP3 to M4B, M4A, or OGG
• Preserves chapters and ID3 tags
• Supports batch processing
• Free and open-source
• Allows metadata editing

❌ Cons

• Windows only
• Requires cumbersome manual setup for beginners

How to Convert AAX to M4B on Windows via AAX Audio Converter [Free]

Another popular free tool is AAX Audio Converter, an open-source project designed specifically for converting Audible AAX audiobooks into M4B or MP3 formats. It preserves chapters, metadata, and cover art while allowing batch conversion. You can also split chapters or correct inaccurate tags during the process. Keep in mind that an activated Audible account and a personal activation code are required, and currently, it's not compatible with macOS.

Step 1. Launch AAX Audio Converter and click "Add" to import your AAX audiobooks.

Step 2. Choose M4B as the target output format and specify whether you want to split the file by chapters or keep it as one complete audiobook.

Step 3. Set the destination folder for saving the converted M4B files.

Step 4. Click "Convert" to start the process. Once finished, you can find the new M4B audiobooks in your output folder.

✅ Pros

• Convert AAX to M4B, MP3, or M4A
• Preserves chapters, tags, and artwork
• Supports batch conversion
• Free and open source

❌ Cons

• May not consistently handle encrypted files

Part 3. Comparison Table: Top AAX to M4B Converters in 2025

Below is a detailed comparison table of the best AAX to M4B converters in 2025. Take a quick look to find your ideal tool for turning Audible AAX files into M4B audiobooks. We've compared each converter based on conversion speed, output quality, supported formats, and more. Check it out to choose the one that suits your needs most.

Features	Kamsker AAX to M4B Converter	AudFree Audible AAX Converter	Audiobook Converter	AAX Audio Converter
Platform	Web	Mac/Windows	Windows	Windows
Input Format	Audible AAX files	Audible online files	Audible AAX files	Audible AAX files
Output Format	M4B, MP3, FLAC	M4B, MP3, FLAC, WAV, M4A, AIFF	M4B, MP3, M4A, OGG	M4B, MP3, M4A
Sound Quality	Medium	Lossless	Medium	Medium
Conversion Speed	Slow to Medium	Fast	Medium	Medium
Batch Conversion	❌	✔	✔	✔
Parameters Resetting	❌	✔	✔	❌
Chapters & ID3 Tags Kept	❌	✔	✔	✔
Price	Free	$10.95/month; lifetime free trial	Free	Free
Rating	⭐️⭐️⭐️⭐️	⭐️⭐️⭐️⭐️⭐️	⭐️⭐️⭐️⭐️	⭐️⭐️⭐️

Part 4. Bonus Tip: How to Convert M4B Back to AAX

The above methods show you how to convert AAX to M4B. But what if you want to reverse the process and convert an M4B file back to AAX? Don't worry - it's also possible. Here's a quick example using a free online converter to help you do it easily.

Step 1. Open your browser and visit https://conversionai.com/file/audio/m4b-mpeg-4-audio-book-file/aax-audible-enhanced-audiobook.

Step 2. In the box labeled "M4B to AAX Converter", set the first dropdown to M4B and the second to AAX.

Step 3. Click the "Convert" button to upload your M4B file and start the conversion process.

Part 5. FAQs about AAX to M4B Conversion

Does converting AAX to M4B keep chapter metadata?

Yes. Professional converters such as AudFree Audible Converter, Audiobook Converter, and AAX Audio Converter preserve chapter information and metadata automatically. The first two tools also let you edit audiobook tags before conversion.

How to change audiobook speed or tags after AAX to M4B conversion?

With tools like AudFree Audible Converter, you can directly edit tags and adjust playback speed. Alternatively, you can use apps such as iTunes, MusicBrainz Picard, or any audiobook editor to modify tags, chapters, or playback rate after conversion.

Can you convert AAX to M4B without losing chapters or quality?

Absolutely. Using AudFree Audible Converter ensures lossless output while keeping full chapter markers and original audio quality intact.

Is there a free AAX to M4B converter available?

Yes. Both Audiobook Converter and AAX Audio Converter are completely free and open-source programs that can convert non-DRM Audible files to M4B with chapters. Additionally, you can try Libation Audible Converter from GitHub - another excellent free option for downloading Audible AAX files to MP3 or M4B formats.

Conclusion

To sum up, converting AAX to M4B in 2025 has never been easier. For a fast and free option, Kamsker Online Converter is a good place to start. However, if you want lossless quality, full chapter preservation, and the ability to handle DRM-protected files, AudFree Audible Converter stands out as the most versatile solution. For free software alternatives, Audiobook Converter or AAX Audio Converter are also excellent choices. With these tools, you can enjoy your Audible audiobooks seamlessly on iTunes, Apple Books, or any compatible player - anytime and anywhere.